Hand held electric tools, also referred to as power tools, are already used extensively for the processing of workpieces in buildings. The workpiece may be a wall, a ceiling, a floor or the like in the building.
Workpieces such as these in buildings are frequently processed by means of a movable appliance, which is controlled by hand. In this case, the user moves the appliance by hand to a predetermined nominal position. It is immediately evident that the processing accuracy can suffer from this. When a plurality of successive nominal positions are intended to be achieved, for example, in order to produce a hole pattern, then this process is not only inaccurate but is also tedious. In particular, in this case, time-consuming measurements of the working area and/or of the workpiece are necessary. It would be possible to reduce the effort involved in work preparation if user-friendly navigation for the appliance were to largely eliminate the measurement of the working area.